That's a low-level C error code. I believe they are standardized via Posix, but if you search on Google, there are some lists online. If you are doing development, you can also look at errno.h provided by the system.
I opened errno.h on my macOS 11.6 system with Xcode installed via the following on the commandline:
open xcrun --show-sdk-path/usr/include/sys/errno.h
it looks like your error is:
#define EAGAIN 35 /* Resource temporarily unavailable */
If you don't close the connection in software correctly, sometimes a crash will level the serial port "busy" and/or maybe something else is using such as the Arduino GUI serial monitor...
I would suggest opening an issue with the [comport] developers asking them to add the output of "strerror(errno))" to the errno print.
On Mar 28, 2022, at 1:35 PM, pd-list-request@lists.iem.at wrote:
Message: 2 Date: Mon, 28 Mar 2022 13:21:58 +0200 From: Jakob Laue <jakkesprinter@web.de mailto:jakkesprinter@web.de> To: Pd-list@lists.iem.at mailto:Pd-list@lists.iem.at Subject: [PD] meaning of [comport]s error numbers Message-ID: trinity-435fb98f-4492-4958-9052-91b2253c8395-1648466518717@3c-app-webde-bap22
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Dear list, I am trying to communicate from Pd Vanilla 0.50.2 to Arduino Mega via USB on Mac. It is still work in progress and sometimes I get error messages from the [comport] object, e.g. 'Write failed for -1 bytes, error is 35'. Does anyone know where I can find the meaning for the different error numbers that [comport] throws? ? ? Thanks, Jakob
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